Talk:Spectroscopy

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To-do list for Spectroscopy: edit · history · watch · refresh
  • Restructure according to guidelines in Wikipedia:WikiProject Science, ie. :
    • start with 2 or 3 paragraphs for the general public, using daily life examples
    • explain the applications of spectroscopy. In particular, explain its importance in the development of physics and many other sciences
    • present the different techniques and their classifications
    • detail the history
Priority 2  

Contents

[edit] QCC

This section does not belong here. It is blatently commercial, gives no details concerning the algorithm and is unclear, to say the least, as to what it does and when it can be applied. It is much too specialised to be in an article which introduces a very broad range of techniquesPetergans 10:23, 24 March 2007 (UTC)

I agree absolutely. Unless there is disagreement, I will remove this section (perhaps to a separate article) in 48 hours. Ignoramibus 23:58, 23 April 2007 (UTC)

[edit] Mass spectroscopy

Mass spectra don't really fit into this definition of spectrosopy. Is this a problem?

On the surface, it would seem so. But, according to Einstein's famous identity, E=mc^2, mass and energy are the same thing. one could, in principle, plot a mass spectrum in energy units rather than in mass units. That this is not done in practice does not overshadow the interchangeability of the units. Particle physicists, for instance, do you energy-derived units as a measure of mass--speaking of how many electron-volts a particle masses, for instance.

Mass spectroscopy is significantly different from the other spectrometers on the page. MS measures the deflection, dependant on mass, of ions in a magnetic field. The plots are of discrete ion-mass (the deflection), against how many of the corresponding atoms are present in the sample (intensity). You couldn't legimately ever put MS results in to an energy/frequency graph. I think it should be treated as an exception. -- sodium

The main difference between mass spectroscopy and the other the types described in the page is that MS is not light spectroscopy. It doesnt involve energy transitions between different quantum states.

[edit] Classification

I've made an attempt to make the haphazard list of examples a bit more structured, but I'm still not completely happy with the result. Ideally, the words in the name of a branch (e.g., X-ray electron spectroscopy), should each fit under one of the four classification schemes. However, in this example, X-ray refers to the frequency parameter AND the measurement process and electron refers to the measurable quantity AND the physical process. Merging into two general classifications does not work, because 'Fourier transform spectroscopy' wouldn't fit.

I'm not sure either that it was a good idea to move everything under electromagnetic spectroscopy to a separate page.

Any suggestions? -- Hankwang 19:03, 17 Mar 2004 (UTC)

Your new classification scheme for spectroscopy isnt dichotomizing very well. Im considering reverting, but it would be better if you could clean it up. Bensaccount 02:49, 22 Mar 2004 (UTC)

[edit] History/Intro

It is not necessary to include the history of spectra on this page. Bensaccount 02:32, 22 Mar 2004 (UTC)

Maybe a history is too much, but according to Wikipedia:The_perfect_article, an article should have an introduction that is comprehensible to nonspecialists without having to look up other articles. I quote:
The perfect Wikipedia article ...begins with a definition or clear description of the subject at hand. This is made as absolutely clear to the nonspecialist as the subject matter itself will allow. ... does not leave essential terminology unexplained, even within the article itself. If some piece of terminology is essential to the subject itself, then it should be explained in the article about that subject, even if it is also explained on another page as well.
The current introduction is too short. -- Hankwang 13:30, 22 Mar 2004 (UTC)

I agree, the introduction is too short but also inaccurate. It describes spectrometry independent of electromagnetic references and then goes on to define it again with reference to "light!" It should be one or the other, or the distinction should be more clear! I think one section for EM spectroscopy and another for "other" types would make things far more clear and "comprehensible to nonspecialists", regardless of exact definitions. Also considering the bulk of the material here (and elsewhere) concerns EM spectroscopy, it would make more sense to me. Biledemon 14:40, 12 July 2006 (UTC)

[edit] SPR

My wife, a biochem major, was looking for a definition of SPR spectroscopy here, but didn't find one. Is it under a different name, or does it need to be added to the article? Jwrosenzweig 01:32, 9 Mar 2005 (UTC)

[edit] Redirect Emission Spectroscopy to Photoemission spectroscopy?

Should the newly inserted link to Emission Spectroscopy be redirected to the Photoemission spectroscopy article ? H Padleckas 04:27, 14 Jun 2005 (UTC)


[edit] Thermal spectral smear?

If a substance is sufficiently hot, will the thermal-kinetic energy of its component atoms smear out its spectral lines? However, according to Boltzmann_distribution#typical speed, a gas would have to be circa 1e15 K for this to be a significant problem, at which point the gas will not be an ideal gas. CS Miller 19:25, July 13, 2005 (UTC)

[edit] Atomic Absorption Spectroscopy

"Atomic absorption spectroscopy (often called AA)"

I would've thought that atomic absorption spectroscopy was often called AAS, not AA.

--thanks

The acronym AAS has also been used for atomic absorption spectroscopy. H Padleckas 06:51, 25 December 2005 (UTC)

[edit] WikiProject Spectroscopy

I just started a new project for Spectroscopy. Please contribute if interested. --Tjr9898 04:00, 21 July 2006 (UTC)

[edit] Definition

I feel that the definition of spectroscopy is too narrrow. Spectroscopy is a very broad topic, so I think the introduction should concentrate on embracing this, and not on narrowing the definition.

Further, if we list all of the things that are called spectroscopy, then the definition should fit them all.

Perhaps it could be something along the lines of: Spectroscopy is the observation of the properties of light, matter and wavelike phenomena. --150.203.177.218 02:18, 16 October 2006 (UTC)

Please feel free to be bold and to make edits that you believe will improve the article!
Atlant 13:25, 16 October 2006 (UTC)

[edit] Spectrometry

The issue of spectroscopy versus spectrometry has come up in several places. I think that wikipedia needs a definition of spectrometry. This could be a short article or incorporated into this one. There are many spectroscopic techniques that have spectrometric variants but there are also spectrometric techniques that are not spectroscopic at all, such as mass spectrometry. I fully expect this to be a difficult and confusing issue for editors and potentially an issue of debate but I think that readers are equally as confused. By the way what is here in terms of a definition is pretty good but too brief and hidden. I would suggest a short article and a smaller section here with a link to it. When the spectrometric variants are discussed here they should be designated as a form of spectrometry but that derives from spectroscopic phenomena. Of course there are many problems distinguishing between these since scientists have not always done a good job of distinguishing and maintaining internally consistent definitions. There will be some cases where there is overlap or cases where a spectrometric technique is named as a spectroscopic technique etc. In these cases we will need to have strong links between these two articles and address the subtleties and misnomers without defying current usage and consensus. I thought I should get some input here before being too bold.--Nick Y. 18:46, 14 December 2006 (UTC)

[edit] Image

The main image of this article is probably soon deleted from Commons, as it is licensed under a NC license. Bryan 20:35, 30 January 2007 (UTC)

[edit] Information

This information was taken excised from the article. It is placed here in case some of it deserves to be readded to this or another article. Srnec 22:44, 5 April 2007 (UTC)

Impedance spectroscopy is a study of frequency response in alternating current.

  • Absorption spectroscopy uses the range of electromagnetic spectra in which a substance absorbs. In atomic absorption spectroscopy, the sample is atomized and then light of a particular frequency is passed through the vapour. After calibration, the amount of absorption can be related to the concentrations of various metal ions through the Beer-Lambert law. The method can be automated and is widely used to measure concentrations of ions such as sodium and calcium in blood. Other types of spectroscopy may not require sample atomization. For example, ultraviolet/visible (UV/ Vis) absorption spectroscopy is most often performed on liquid samples to detect molecular content and infrared (IR) spectroscopy is most often performed on liquid, semi-liquid (paste,grease,and petroleum jelly), dried, or solid samples to determine molecular information, including structural information.
  • Emission spectroscopy uses the range of electromagnetic spectra in which a substance radiates. The substance first absorbs energy and then radiates this energy as light. This energy can be from a variety of sources, including collision (either due to high temperatures or otherwise), and chemical reactions.
  • Scattering spectroscopy measures certain physical properties by measuring the amount of light that a substance scatters at certain wavelengths, incident angles, and polarization angles. Scattering spectroscopy differs from emission spectroscopy due to the fact that the scattering process is much faster than the absorption/emission process. One of the most useful applications of light scattering spectroscopy is Raman spectroscopy.


[edit] Joseph von Fraunhofer

There should be some informations over Joseph von Fraunhofer in the article.

[edit] Inaccuracy of the article

I think the excision of a whole bunch of spectroscopic techniques is severely at odds with what spectroscopy is commonly taken to mean as is the 'definition' that the article gives. That definition must have been taken from a 1911 encyclopdia or so? At any rate it makes the article scientifically misleading and incorrect

In modern science spectroscopy can refer to any measurement performed where wavelength or frequency are systematically varied.

Jcwf (talk) 00:19, 14 January 2008 (UTC)

[edit] Circular Dichroism

There are good articles on circular dichroism and magnetic circular dichroism. Is there a reason they are not included in the types of spectroscopy or in the list at the end? Woops, circular dichroism is mentioned. Should magnetic be mentioned? It is similar, but has very distinct applications. BobertWABC (talk) 22:39, 4 March 2008 (UTC)